Instructions for installing the fixfits task.

Set ftp binary mode before downloading fixfits.tar.Z

---------

First, unpack the tar file:

    % cd <some parent directory>
    % zcat fixfits.tar.Z | tar -xvpf -

This will create a subdirectory fixfits containing the source file,
t_fixfits.x, the compiled SunOS Sparc executable, t_fixfits.e, and
the parameter file fixfits.par.

---------

A simple SPP program that replaces negative values in an image with
the (value + 65536).  This has been useful for people with non-standard
FITS tape where BITPIX=16 was used to represent 16-bit unsigned integers.

RFITS, with default parameters, creates an IRAF image with signed integer
pixels in the range -32768 to 32767 from such a FITS file.  The intended
pixels can be recovered by adding 65536 to each negative pixel.

The sparc binaries are included in the tar file.  If necessary for another
system, build the task with these commands:

        cl> rm t_cafix.o t_cafix.e
        cl> xc t_cafix.x

The task can be declared with this command (which can also be placed into
your loginuser.cl or login.cl file):

        cl> task cafix = <directory>/t_cafix.e

Then, 
        cl> cafix <images> 

runs the task, fixing the named images in-place.